Radioactivity: always and everywhere

Radioactivity and ionising radiation are natural phenomena always present in the natural environment.
In our daily lives we are confronted with various significant radiation sources: cosmic radiation, natural radioactive substances and medical applications of ionising radiation.
The millisievert is the unit that quantifies the level of potential radiation damage to the human body, also referred to as the dose.

In Belgium the average exposure to ionising radiation is 4.6 millisievert per annum.